HMB is also known as beta-hydroxy-beta-methyl butyrate. It is a metabolite of the essential amino acid leucine via α-ketoisocaproate (KIC), the transamination product of leucine, which seems to decrease muscle breakdown. This effect on the breakdown of muscles is why HMB is used as an ergogentic aid/ dietary supplement (any external influences that can be determined to enhance performance) by bodybuilders, as well as athlete(1). Other ways it can be consumed other than through some kind of supplement, is by consuming it through plant and animal foods; like grape fruit and catfish(1). HMB is also a supplement that is not a banned or restricted substance by the International Olympic Committee and it is also not on the 2010-2011 NCAA Banned Drugs list(2). Those who use HMB are seeking to promote enhanced muscle gains in strength and lean body mass, which can result from resistance type training(3).
Science of HMB:
This supplement is believed to be able to influence strength, along with lean body mass, by acting as an anticatobolic agent. This is done when leucine is ingested by the body it is transmitted into KIC (α-ketoisocaproate); which appears to decrease the amount of muscle broken down by the body. The KIC is believed to either be metabolized into isovaleryl-CoA in the mitochondria or into HMB in the cytosol, where approximately 5% of the leucine is metabolized into HMB(1). Since HMB contains leucine, it carries the unique characteristic that leucine has in the regulation of protein synthesis and degration. With this, the agent is believed to minimize the protein breakdown in the body. Along with it playing a role in protein breakdown, it also possesses the characteristic of being able to decrease the damage to cells that can be seen during an intense exercise. Also, with the increase of KIC that is transmitted from leucine and the potential outcome of this being HMB, it is found that the increased amount of KIC will in turn increase the rate of protein synthesis and decrease the rate of protein degration(3).
Studies of HMB:
Animals: Most of the initial research done with HMB was done on animals. A study done on chickens showed that there was an increase in body weight in those that were given HMB in their feed, compared to the chickens on a control diet. More research was done on under fed lambs, and when supplemented with HMB they had a 102% catch up rate of growth. Both these studies showed that when the animals were introduced to a catabolic environment with food restriction and then supplemented on HMB, they were able to increase their rate of growth(3).
Human Studies: One study consisted of untrained volunteers that underwent a three week weight training program. Throughout these three weeks the subjects were given a dose of HMB, either 0, 1.5, or 3g/day. The study looked at the response of the body to the different doses. The conclusion of the test was that HMB supplementation reduced muscle damage that was linked to exercise. Other tests concluded that those who took HMB, regardless of sex, responded fairly similar to the supplement when taking it. HMB has also been associated with reducing muscle loss that is linked to diseases of an auto immunodeficiency kind, as well as cancerous conditions(3). There have also been studies done on the elderly that had them take HMB as they performed a resistance training program. This program was performed for several weeks by the elderly that were given HMB and well as some were given a placebo. At the end of the study, the results showed that the loss of body fat was greater in those who took HMB than the placebo. The people who took the placebo also had less upper and lower body strength than those who took the HMB. Other studies have shown similar results to this one, including one on the elderly and bed rest that showed how supplementation helped decreased performance decrements seen in bed rest patients(1).
This is a chart from a study done on untrained individuals and the affects it had on them after resistance training.
HMB supplementation in untrained individuals: Effect on indicators of muscle damage following exercise* (4)
Study
Participants
Supplementation
Biochemistry
Nissen et al11
41 M
P, HMB:1.5 or 3 g/day for 3 weeks
Decrease in CPK at wk 3, trend for decreased LDH at wks 2-3, decreased 3-MH at wk 2 only.
Jowko et al15
40 M
P, HMB 3g/d, CR, HMB+CR for 3 wks
Decreased CPK with HMB at 2 wks only
Gallagher et al16
37 M
P, HMB:38 or 76 mg/kg/d for 8 wks
Decreased CPK in both HMB groups at 48h only; no effect at other points in study.
van Someran et al17
6 M
P, HMB+KIC (3g/0.3g) for 14d prior to bout of eccentric exercise
Decreased CPK in first 48h following exercise.
Paddon-Jones et al18
17 M
P, HMB 40mg/kg/d For 6d prior to bout of eccentric exercise
It has been found that doses greater than 100g had no adverse effects when given to animals. However, those animals also had no increased enhancements from taking that much HMB. In human studies, on another hand, it has been shown that there were no further enhancements from taking HMB once the dose was greater than 3g per day in individuals that were being studied for dosage response. Recommended dosage of HMB is usually between 1.5 and 3g per day(1,3).
Conclusion:
HMB is a supplement that is can be used by trained and untrained individuals. It has been shown to help people increase their strength and muscle mass with an establishment of a resistance training program. Those who have not been exercising and then start a training program see high enhancements with the help of HMB. Others who already had a training program in place and started taking HMB also showed increased fat loss and increased strength. It can also help people who have diseases that cause muscle loss by slowing down the process of muscle breakdown. When it comes to taking HMB there are no adverse side effects from it; even with no negative effects it is still recommened to not take more than 3g per day.
1.Wilson, G., Wilson, J., & Manninen, A. (2008). Effects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A review.Nutrition & Metabolism, 51-17.doi:10.1186/1743-7075-5-1. 2.O'Connor, D., & Crowe, M. (2007). EFFECTS OF SIX WEEKS OF β-HYDROXY-β-METHYLBUTYRATE (HMB) AND HMB/CREATINE SUPPLEMENTATION ON STRENGTH, POWER, AND ANTHROPOMETRY OF HIGHLY TRAINED ATHLETES. Journal of Strength & Conditioning Research (Allen Press Publishing Services Inc.), 21(2), 419-423. Retrieved from Academic Search Premier database. 3.Slater, G., & Jenkins, D. (2000). β-Hydroxy-F128b-Methylbutyrate (HMB) Supplementation and the Promotion of Muscle Growth and Strength. 4.Routhier, D., & Stacy, J. (2007). HMB use and its relationship to exercise-induced muscle damage and performance during exercise. International SportMed Journal, 8(2), 68-77. Retrieved from Academic Search Premier database. 5.http://www.olimp-supplements.com/images/produkty_en/hmb450.jpg 6.http://www.a1nutrition.com/g/graphics/products/eas/hmb.jpg 7.http://images.swansonvitamins.com/en_US/images/ItemImages_SW/images_sf/TL645_sf.jpg 8.http://www.youtube.com/watch?v=mt-TMy10OBk
(5)
HMB:
HMB is also known as beta-hydroxy-beta-methyl butyrate. It is a metabolite of the essential amino acid leucine via α-ketoisocaproate (KIC), the transamination product of leucine, which seems to decrease muscle breakdown. This effect on the breakdown of muscles is why HMB is used as an ergogentic aid/ dietary supplement (any external influences that can be determined to enhance performance) by bodybuilders, as well as athlete(1). Other ways it can be consumed other than through some kind of supplement, is by consuming it through plant and animal foods; like grape fruit and catfish(1). HMB is also a supplement that is not a banned or restricted substance by the International Olympic Committee and it is also not on the 2010-2011 NCAA Banned Drugs list(2). Those who use HMB are seeking to promote enhanced muscle gains in strength and lean body mass, which can result from resistance type training(3).
Science of HMB:
This supplement is believed to be able to influence strength, along with lean body mass, by acting as an anticatobolic agent. This is done when leucine is ingested by the body it is transmitted into KIC (α-ketoisocaproate); which appears to decrease the amount of muscle broken down by the body. The KIC is believed to either be metabolized into isovaleryl-CoA in the mitochondria or into HMB in the cytosol, where approximately 5% of the leucine is metabolized into HMB(1). Since HMB contains leucine, it carries the unique characteristic that leucine has in the regulation of protein synthesis and degration. With this, the agent is believed to minimize the protein breakdown in the body. Along with it playing a role in protein breakdown, it also possesses the characteristic of being able to decrease the damage to cells that can be seen during an intense exercise. Also, with the increase of KIC that is transmitted from leucine and the potential outcome of this being HMB, it is found that the increased amount of KIC will in turn increase the rate of protein synthesis and decrease the rate of protein degration(3).
Studies of HMB:
Animals: Most of the initial research done with HMB was done on animals. A study done on chickens showed that there was an increase in body weight in those that were given HMB in their feed, compared to the chickens on a control diet. More research was done on under fed lambs, and when supplemented with HMB they had a 102% catch up rate of growth. Both these studies showed that when the animals were introduced to a catabolic environment with food restriction and then supplemented on HMB, they were able to increase their rate of growth(3).
Human Studies: One study consisted of untrained volunteers that underwent a three week weight training program. Throughout these three weeks the subjects were given a dose of HMB, either 0, 1.5, or 3g/day. The study looked at the response of the body to the different doses. The conclusion of the test was that HMB supplementation reduced muscle damage that was linked to exercise. Other tests concluded that those who took HMB, regardless of sex, responded fairly similar to the supplement when taking it. HMB has also been associated with reducing muscle loss that is linked to diseases of an auto immunodeficiency kind, as well as cancerous conditions(3). There have also been studies done on the elderly that had them take HMB as they performed a resistance training program. This program was performed for several weeks by the elderly that were given HMB and well as some were given a placebo. At the end of the study, the results showed that the loss of body fat was greater in those who took HMB than the placebo. The people who took the placebo also had less upper and lower body strength than those who took the HMB. Other studies have shown similar results to this one, including one on the elderly and bed rest that showed how supplementation helped decreased performance decrements seen in bed rest patients(1).
This is a chart from a study done on untrained individuals and the affects it had on them after resistance training.
HMB supplementation in untrained individuals: Effect on indicators of muscle damage following exercise* (4)
3 weeks
wk 3, trend for
decreased LDH at
wks 2-3, decreased
3-MH at wk 2 only.
HMB+CR for 3 wks
HMB at 2 wks only
8 wks
both HMB groups at
48h only; no effect at
other points in study.
14d prior to bout of eccentric
exercise
first 48h following
exercise.
For 6d prior to bout of
eccentric exercise
LDH= lactate dehydrogenase; 3-MH= 3-Methylhistadine; CR=creatine;
Dosage of HMB:
It has been found that doses greater than 100g had no adverse effects when given to animals. However, those animals also had no increased enhancements from taking that much HMB. In human studies, on another hand, it has been shown that there were no further enhancements from taking HMB once the dose was greater than 3g per day in individuals that were being studied for dosage response. Recommended dosage of HMB is usually between 1.5 and 3g per day(1,3).
Conclusion:
HMB is a supplement that is can be used by trained and untrained individuals. It has been shown to help people increase their strength and muscle mass with an establishment of a resistance training program. Those who have not been exercising and then start a training program see high enhancements with the help of HMB. Others who already had a training program in place and started taking HMB also showed increased fat loss and increased strength. It can also help people who have diseases that cause muscle loss by slowing down the process of muscle breakdown. When it comes to taking HMB there are no adverse side effects from it; even with no negative effects it is still recommened to not take more than 3g per day.
Links of HMB:
http://images.swansonvitamins.com/en_US/images/ItemImages_SW/images_sf/TL645_sf.jpg (7)
References:
1.Wilson, G., Wilson, J., & Manninen, A. (2008). Effects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A review.Nutrition & Metabolism, 51-17.doi:10.1186/1743-7075-5-1.
2.O'Connor, D., & Crowe, M. (2007). EFFECTS OF SIX WEEKS OF β-HYDROXY-β-METHYLBUTYRATE (HMB) AND HMB/CREATINE SUPPLEMENTATION ON STRENGTH, POWER, AND ANTHROPOMETRY OF HIGHLY TRAINED ATHLETES. Journal of Strength & Conditioning Research (Allen Press Publishing Services Inc.), 21(2), 419-423. Retrieved from Academic Search Premier database.
3.Slater, G., & Jenkins, D. (2000). β-Hydroxy-F128b-Methylbutyrate (HMB) Supplementation and the Promotion of Muscle Growth and Strength.
4.Routhier, D., & Stacy, J. (2007). HMB use and its relationship to exercise-induced muscle damage and performance during exercise. International SportMed Journal, 8(2), 68-77. Retrieved from Academic Search Premier database.
5.http://www.olimp-supplements.com/images/produkty_en/hmb450.jpg
6.http://www.a1nutrition.com/g/graphics/products/eas/hmb.jpg
7.http://images.swansonvitamins.com/en_US/images/ItemImages_SW/images_sf/TL645_sf.jpg
8.http://www.youtube.com/watch?v=mt-TMy10OBk